Hi David, Kieran here from Cork, Ireland. I am currently 2nd Dan [Aiki No Michi] and opened my own club last year. The issue you bring up brings up lots of memories for me when I started Aikido 11 years ago. I was so nervous about gradings I didnt partake in my first one for 3 years and watched all my contempories move forward. But the interesting thing is that I am possibly the only one left training after all this time. What I am trying to say is that it is not the grade that matters it is the work that YOU put in. Gradings for me are not to let others see how much you know, but instead to show yourself what you know inside.
Hope that helps, Kieran